Two-dimensional dopant characterization using SIMS, SCS and TSUPREM4

Abstract

Quantitative two-dimensional (2D) dopant profiling for 0.25 micron CMOS technology was demonstrated using secondary ion mass-spectrometry (SIMS) and scanning capacitance spectroscopy (SCS). P-well and N-well dopant profiles measured by 2D SIMS are in agreement with TSUPREM4 (TS4) simulations. TS4 was pre-calibrated to the specific technology using 1D SIMS and electrical data. 2D SIMS, TS4 and SCS show agreement on the well boundary location. SCS is an advanced form of scanning capacitance microscopy (SCM) devised for pn-junction delineation. 2D SIMS dopant profiling with lateral resolution of 10 nm (limited by the lithography pixel size) and sensitivity of 1~1 0 '~ cm" was realized on commercial equipment. \ IntroductionThe goal of this study is to demonstrate capabilities of recently developed two-dimensional (2D) secondary ion mass-spectrometry (SIMS) and scanning capacitance spectroscopy (SCS) techniques for quantitative 2D dopant analysis. SIMS is the only doping characterization technique that directly measures dopant concentration. 2D SIMS was invented by Hill, Dowsett and Cooke (1) and improved lately by using a MoirC pattern design for the test structure (2).

Series resistance calculation for source/drain extension regions using 2-D device simulation

“…All major assumptions of the methods have to be examined for their impact, and relaxed if necessary. 16 Alternatively, one can treat the extraction method as the definition of electrical quantities, to be used only in a context that is consistent with the extraction method [14], and rely instead on physical techniques such as those described in [15]- [17] for obtaining physical quantities.…”

“…The key to note is that the difference between the two terms in (12) lies in the fact that the latter is proportional to . Due to counter-doping and short channel effects, 15 the edge of the channel behaves differently from the center, and is not scaled with channel length. The extraction routine cannot distinguish between this and the source/drain resistance, thus it lumps the former with the latter.…”

Perspectives on technology and technology-driven CAD

“…Moreover, metrology for 2-D profile characterization is an open issue with no definitive solution. Progress in both the modeling and measurements of shallow junctions, while encouraging [10]- [12], is still far from routine or sufficient to fully support the ongoing experimental challenges of scaling. During the late 1990s, the importance of electrical effects other than those of the intrinsic devices and gate delays, especially the role of interconnect and substrate parasitics, became a major concern.…”